This invention relates to machine tool securement and fastening systems and particularly to a securement system for use with replacable machine tool cutting inserts. The invention is particularly useful for adjustably securing the cutting inserts of various cutting tools used in the machining industry.
Boring bars, porting tools, turning tools and other cutting means are used in the machining industry to cut apertures and surfaces in metal or other work pieces in the construction of machine parts. These cutting devices are relatively expensive and prone to wear out over time due to frictional forces generated by contact with, and the cutting of solid metal work pieces. Therefore, they are typically configured to have a replaceable cutting member or insert. In some tools, such as the boring bar, the entire head portion or end is replacable as well. This invention deals particularly with an adjustable securement system for replaceable inserts on either fixed or replaceable tool heads of machine tools.
Replaceable cutting inserts are typically fixed to the working end or head of the tool and contact the work piece for cutting and boring purposes. Such inserts are typically constructed of a carbide material or the like. Although various types of boring and porting structures are known and used, their configurations are generally similar in nature. The carbide inserts typically have a quadrilateral or triangular configuration, and are typically screwed into a threaded aperture in the head of the structure.
However, this structure has significant limitations with respect to long term effectiveness of the tool in use. Specifically, the tolerances required by the cutting inserts are typically approximately plus or minus 0.003 inches (0.008 cm.) and, thus, they must be securely held in place so that the cutting edge of the insert does not move, particularly under the stresses encountered in the cutting environment. Also, because wear on the insert is inevitable and deleterious to precision machining processes, it would be advantageous if the position of the insert is adjustable to accommodate for such wear. And further, it would be advantageous if such securement and adjustment is easily accomplished by the machinist. However, the structures known in the prior art typically fall short of these needs. Such structures typically do not provide for ease of attachment and therefor are difficult to use. Also, such structures often do not provide for a secure attachment and therefore, are either prone to frequent failure or require frequent inspection and retightening. Finally, prior art structures do not provide for position adjustment, and therefore require frequent insert replacement due to normal wear of cutting surfaces.
Despite the need for an adjustable securement structure in the art which overcomes the limitations and shortcomings of the prior art, none insofar as is known has been proposed or developed. Accordingly, it is an object of the present invention to provide a cutting insert securement structure which securely fastens and holds a removable cutting insert in an operative orientation on a machine tool, which may be adjusted, and which securement and adjustment is easily accomplished by the machinist.